Method and apparatus for making terminals and for attaching the same to conductors

ABSTRACT

A METAL STRIP IS INTERMITTENTLY FED THROUGH AN APERTURE FORMING STATION TO AN ATTACHING STATION. PROGRESSIVE TOOLS AT THE FORMING STATION PUNCH APERTURES IN THE STRIP TO LEAVE CONNECTED TERMINAL BLANKS. AT THE ATTACHING STATION, THE BLANKS ARE SEQUENTIALLY SEVERED FROM THE STRIP, A PORTION OF EACH BLANK IS BENT INTO AN APPROXIMATE U-SHAPE, AND THEN FORCED INTO A CRIMPING DIE WHICH CLAMPS THE BENT BLANK PORTION OVER A CONDUCTOR INTRODUCED INTO THE DIE.

Sept. 20, 1971 A N ETAL 3,605,261

METHOD AND APPAuATus FOR MAKING TERMINALS AND FOR ATTACHING THE SAME TO counuc'rons Filfld NOV. 3, 1969 3 Sheets-Sheet l INVILNI 0R3 IRWIN ZAHN ARTHUR GRAF IRVING W. ROSENBAUM BY WMM AGENTS Sept. 20, 1971 ZAHN ETAL 3,605,263

METHOD AND APPARATUS FOR MAKING TERMINALS AND FOR ATTACHING THE SAME TO CONDUCTORS Filed Nov. 3, 1969 3 Sheets-Sheet 2 33 FIG.2

INVIL'N'I NR3. IRWIN ZAHN ARTHUR GRAF IRVING W. ROSENBAUM WWW AGENTS 3 Sheets-Sheet 3 l. ZAHN m- IE'I'HOD AND APYARATUS FOR MAKING TERMINALS AND IOR ATTACHING THE SAIB TO CONDUCTORS FIG 4 l 1 no Sept. 20, 1971 um Nov. 3, 1969 FIG.5

INVIL'N'I (IRS. mwm mm ARTHUR GRAF I IRVING W. RO SENBAUM BY Mud/1L M W AGENTS Patented Sept. 20, 1971 3,605,261 METHOD AND APPARATUS FOR MAKING TERMINALS AND FOR ATTACHING THE SAME T CONDUCTORS Irwin Zahn, Arthur Graf, and Irving W. Rosenbaum, New York, N.Y., assignors to Genstape, Inc., New York, N.Y.

Filed Nov. 3, 1969, Ser. No. 873,400 Int. Cl. H01r 43/00, 43/04 US. Cl. 29-628 12 Claims ABSTRACT OF THE DISCLOSURE A metal strip is intermittently fed through an aperture forming station to an attaching station. Progressive tools at the forming station punch apertures in the strip to leave connected terminal blanks. At the attaching station, the blanks are sequentially severed from the strip, a portion of each blank is bent into an approximate U-shape, and then forced into a crimping die which clamps the bent blank portion over a conductor introduced into the die.

This invention relates to terminals for electrical conductors, and particularly to a semi-automatic or automatic machine for making and attaching the terminals, and to its method of operation.

It is known to convert continuous metal strip into connected terminal blanks on a forming machine and to feed the blanks to attaching machinery which sequentially severs individual blanks from the remainder of the connected blanks and the strip, and clamps each severed blank to a conductor presented to the machine by an operator or by automatic devices. -It was not practical heretofore to combine the known blank forming and blank attaching devices in a single machine, and it was necessary to store the strip of blanks prior to attaching. Because of the requirements of the known commercial attaching machines, the blanks could not be supplied flat but had to be preshaped by bending them in a plane perpendicular to the direction of strip elongation.

A terminal attaching machine cannot be operated economically unless the strip of blanks is of great length so as to include the material for a thousand or more blanks. A strip of such length cannot be handled in a practical manner unless it is coiled, and it is difficult to coil a strip of transversely bent blanks and to handle the coil without distorting the strip in a manner to cause malfunctioning of the attaching machine.

The primary objects of this invention are a terminal making and attaching method which makes it unnecessary to coil a strip of transversely bent blanks, and the provision of apparatus for performing the method.

Another, more general object is a reduction in the cost of attached terminals.

With these and other objects in view, as will hereinafter become apparent, the invention, in one of its aspects, mainly resides in a method of making terminals and of attaching the terminals to respective conductors in which acontinuous elongated strip is intermittently fed through an aperture forming station to an attaching station in a plurality of successive steps, whereby respective, integrally connected, first and second longitudinal portions of the strip are simultaneously stationary at the two stations between the feeding steps. An aperture is formed in each of the first portions at the forming station, and each second portion is severed from the remainder of the strip at the attaching station to constitute a blank. The blank is moved in a direction transverse to the elongation of the strip, and a part of the blank is draped over an anvil at the attaching station to bend the part into an approximate U-shape. A conductor is introduced into a die, and the approximately U-shaped blank part is clamped on the conductor in the die. The transverse moving of the blank, and the draping and clamping of the blank portion is performed in a single, straight and continuous stroke between two successive steps of the feeding movement.

In another aspect, the invention resides in apparatus for performing the afore-described method which cornprises a feeding device for intermittently moving an elongated strip in a longitudinal path. An aperture forming station at the path includes a tool assembly and guides for guiding the tool assembly transversely of the path for piercing engagement with a moving strip. An attaching station at the path, which is spaced from the aperture forming station in the direction of strip movement, includes a cutting device for transversely cutting a blank from the pierced strip, a bending device for bending a part of the blank into an approximate U-shape, a die whose cavity is open toward the bending device for receiving the bent part of the blank, means in the die for clamping the bent blank part about a conductor introduced into the die cavity when the bent blank enters the cavity, and a ram which forces the bent blank into the cavity. A common drive operates the feeding device, the tool assembly, the cutting device, the bending device, and the ram in the necessary timed sequence.

Other features, additional objects and many of the attendant advantages of this invention will readily become apparent from the following detailed description of a preferred embodiment when considered in connection with the attached drawing in which:

FIG. 1 shows a terminal making and attaching machine of the invention in front elevation, a cover being removed to reveal internal structure;

FIG. 2 shows a portion of the drive arrangement of the apparatus of FIG. 1 in fragmentary side elevation;

FIG. 3 illustrates operating elements of the apparatus of FIG. 1 in fragmentary side elevation on a scale larger than that of FIGS. 1 and 2;

FIG. 4 illustrates the device of FIG. 3 in further enlarged section on the line IVIV;

FIG. 5 illustrates a work piece processed in the apparatus in a view corresponding to that of FIG. 4; and

FIG. 6 shows a terminal made and attached to a conductor in the apparatus of FIGS. 1 to 5.

Referring initially to FIG. 1, there is seen a semiautomatic machine of the invention for making eyeletshaped terminal lugs and for attaching the lugs to the ends of conductors. The machine has many features in common with the wire splicing apparatus disclosed and claimed by one of us in the commonly owned application, Ser. No. 810,759, filed on Mar. 26, 1969, and theattaching station of the instant machine is closely analogous to the earlier wire splicing apparatus.

The frame or stand 1 of the machine supports all operating elements. The stand normally rests on a horizontal work bench or table, not itself shown. An electric motor 2 mounted atop the stand is controlled by a toggle switch 3 on a control box 4 mounted on the stand 1. The output shaft of the motor rotates continuously during use of the machine. A belt 5 connects the motor 2 with the input pulley 6 of a single revolution clutch, not otherwise shown in detail. A pedal switch 7 is wired to the non-illustrated triggering solenoid of the clutch through the control box 4 in a conventional manner to connect the output shaft 8 of the clutch to the pulley 6 for one revolution when the switch 7 is closed.

A reel 9 rotatable on the frame 1 carries a coiled brass strip or fiat wire 10 whose free end passes over an arcuate guide 11 and between two identical feed cams 12 into a metal tube 13 leading to the aperture forming station of the machine which includes a die plate 14 and a stripper plate 15 fixedly mounted on the frame 1, a tool carrier 16, piercing tools 19 and a guide pin 20 fixedly mounted on the carrier, and a registration pin, as will presently be described in more detail.

Operating elements of the attaching station which are visible in FIG. I include a crimping die 17 fixedly mounted in a guide groove 18 of the frame 1 and a bending tool assembly 21. A notch or cavity 22 in the die 17 which is open at right angles to the plane of FIG. l in both directions and toward the bending tool assembly 21 is freely accessible for insertion of the conductor on which a terminal lug is to be attached. It tapers inwardly.

An anvil 23 is obscured in FIG. 23 by a leaf spring 24 attached to the front face of the die plate 14 by a screw 25. The anvil is slidably received in a horizontal guide opening in the die plate 14 and is normally held by the spring 25 in the longitudinal path of the tool assembly 21. The latter slides in aligned passages of the tool carrier 16, the stripper plate 15, and the die plate 14, and thereby guides the tool carrier toward and away from the stripper plate. Further guidance is provided by the rectangular pin 20 fixed on the tool carrier 16 and conformingly received in passages of the plates 14. 15.

Each feed cam 12 is mounted on a shaft 27 and has a circularly arcuate cam face 28 approximately centered in the axis of the shaft 27 and having a length of about 90. A slot 29 extending from one end of the face 28 approximately along the chord of the face into the body of each cam 12 gives some resiliency to the circularly arcuate cam portion whose radius is approximately equal to half the center-to-center spacing of the shafts 27.

The shafts 27 are connected with each other and with the output shaft 8 by a gear train of which only a spur gear 30 on the shaft 8 is indicated in FIG. I, and which turns the shafts 27 for one revolution in opposite directions when the switch 7 is closed momentarily. Set screws, not seen in FIG. 1, permit the earns 12 to be angularly adjusted on the shafts 27. The cams 12 feed the strip 10 into the tube 13 as long as the cam faces 28 cooperate to grip the strip. The length of the cooperating portions, and the corresponding length of the strip 10 which is fed into the tube 12 during each revolution of the shaft 8 may thus be adjusted by the setting of the earns 12.

The tool carrier 16 is fixedly attached to an elongated. plate-shaped slide 31 superimposed on two similar slides 32, 33 in a common upright guide groove 34 of the frame 1 which is normally closed by a non-illustrated cover. The slide 33 which is deepest in the groove 34 is not seen in FIG. 1. The slide 31 has a longitudinal slot 35 in which a boss 36 fixed on the slide 32 is movably received.

The slides 32, 33 are reciprocated longitudinally once during each revolution of the shaft 8 as is shown in FIG. 2. An axial crank pin 37 projects eccentrically from the gear 30. Two heavy links 38, 39 are freely pivoted on the pin 37 and on respective pins 40, 41 on the slides 32, 33.

As is better seen in FIG. 3, the bending tool assembly 21 is fixedly mounted between the longitudinal rear face of the slide32 and a rearwardly projecting boss 42 on the slide 32 in longitudinal alignment with the slide 33. The assembly 21 has the approximate shape of an elongated, hollow prism. A narrow blade or ram 43 pro jects downwardly from the slide 33 into the interior channel of the bending tool assembly. The boss 42 carries the aforementioned registration pin 26. A longitudinal slot 45 extends from the front face of the tool assembly 21 into the channel 44 over the portion of the assembly which extends downwardly from the anvil 23 in the lowermost position of the slide 32 illustrated in FIG. 3 in which the tool assembly 21 projects downwardly from the die plate 14 and is contiguously adjacent the crimping die 17.

The lowermost portion of the slot 44 is laterally enlarged, and the enlargement is upwardly bounded by an oblique cam face 46 matching a cam face 47 on the anvil 23. During downward movement of the bending tool assembly, the anvil 23 is pushed out of the channel 44 when the cam faces 46, 47 engage each other.

The free end of the strip travels in a shallow groove 48 in the bottom face of the stripper plate 15, and strip movement is limited by abutting engagement with a transverse end wall of the groove.

The configurations of the bending tool assembly 21 and of the piercing tools 19 are shown in FIG. 4. The tools 19 consist of a cylindrical punch 19:: approximately equal in cross section to the registration pin 26 which follows the punch 19a in the direction of strip movement indicated by an arrow in FIG. 4. The path of the strip over the illustrated top face of the die plate 14 toward the attaching station is indicated in FIG. 4 by chain dotted lines.

Two trimming punches 19b, 19c are spaced from each other transversely of the direction of strip movement and are followed by a cut-off punch 19a.

The channel 44 in the bending tool assembly 21 is approximately keyhole-shaped in cross section, the center of the cylindrical channel portion being aligned with the centers of the openings in the die plate 14 which receive the punch 19a and the registration pin 26 in the condition of the apparatus seen in FIG. 4. Two ribs 49 projecting into the narrow portion of the channel from opposite walls 50 contiguously adjacent the cylindrical channel portion guide the blade or ram 43. The ram has a somewhat thicker part in the cylindrical channel portion and its thickness in the narrow channel portion is equal to the width of the operating portion 51 of the anvil 23. The side face of the bending tool assembly directed toward the moving strip has a frontal shearing edge cooperating with a shearing blade 52 on the die plate 14.

The stripper plate 15, not shown in detail in the drawing, is provided with openings which permit the punches 19a, 19b, 19c, 19d to pass from the tool carrier 16 into downwardly open, respective passages in the die plate 14, and to pass the registration pin 26 and the bending tool assembly 21 which are fixedly fastened to the slide 32.

The strip 10 is fed forward by the cams 12 in steps as equal as possible to the center-to-center spacing of the openings in the die plate 14 which receive the punch 19a and the registration pin 26 in the view of FIG. 4. An excessive feeding movement of the strip 10 is prevented by abutting engagement of the front edge of the strip with the end wall of the groove 48. The slides 31, 32, 33 are in their topmost positions during each feeding step. The condition of the front end of the strip 10 at this stage is seen in FIG. 5.

After completion of the feeding step, the slide 32 moves downwardly, and the conically tapering bottom end of the registration pin 26 engages the round opening 53 pierced by the punch 19a in a preceding cycle. The longitudinal position of the portions of the strip in the aperture forming station under the tools 19a, 19b, 19c, 19d and at the attaching station is thereby precisely adjusted. The tube 13 is dimensioned to permit the slight buckling of the strip 10 which may result from the adjustment.

During further downward movement of the slide 32, the shearing blade 52 severs a previously formed blank 54 at the front end of the strip by cutting across an otherwise imperforate edge portion of the strip as indicated by a broken line 55. The severed fiat blank 54 consists of an eyelet portion 56 and an approximately T-shaped portion. The eyelet portion is dimensioned to move freely in the cylindrical portion of the channel 44. The web of the T- shaped portion passes between the internal ribs 49 of the bending tool assembly 21. The flanges of the T-shaped portion are draped by the walls over the operating portion 51, of the anvil 23, and are thereby bent into an approximate U-shaped staple.

The downward speed of the slide 33 now exceeds that of the slide 32, and the ram 43 moves downwardly in the channel 44. When it engages the top face of the partly bent blank, the anvil 23 is moved out of the rams way by the cam faces 46, 47, and the blank is pushed toward the lower end of the channel 44. The staple part is forced by the ram 43 into the cavity 22 of the die 17 while the slide 32 is in its lowermost position seen in FIG. 3, and the legs of the staple are crimped by the walls of the cavity about one or more conductors inserted in the die cavity by an operator or an automatic feeder, the crimping operation being described in more detail in the afore-mentioned copending application.

While the bending tool assembly 21 approaches the die 17, the boss 36' abuts against an end wall of the slot 35, and the slide 31 together with the fixedly attached tool carrier 16 makes its short downward stroke in which the punch 19a pierces another circular opening 53 in the strip 10, the trimming punches 19b, 19c remove strip material about the outer circumference of an eyelet 56, and the cutoff punch 19d removes a bridge 57 connecting two consecutive eyelets and left by the trimming punches.

The slides 32, 33 move upwardly to release the finished terminal 57 and the conductor 58 previously introduced into the cavity 22 to which the terminal has been attached as is shown in FIG. 5. When the slide 32 approaches the upper end of its stroke, the slide 33 is taken along by the boss 36, and the several punches 19 are lifted from the strip 10. The stripper plate 15 prevents the strip from moving upwardly with the piercing tools. The registration pin 26 is withdrawn from the strip approximately simultaneously.

The shaft 8 makes one revolution from the feeding of the strip 10 by cams 12 to the withdrawal of all tools from the path of the strip, and stops. The machine is now ready for the next cycle of operations which may be started by an operator who inserts another conductor 58 in the die cavity 22 and closes the pedal switch 7. His intervention in the operation of the machine is otherwise limited to replacing'an e-mpty reel 9 with a full one from time to time. Automatic feeders are available for sequentially feeding conductors to the die cavity 22, and may further reduce the operators part in the process of making and attaching terminals. The pedal switch 7 may be replaced in the fully automatic version of the illustrated machine by a limit switch on the feeding device or at the die 17 to trip the clutch of the machine upon insertion of a conductor. If two or more conductors are simultaneously introduced into the cavity 22, they are spliced to each other by the attached terminal.

In an actual embodiment of the invention which has been operated successfully for making eyelet terminals having an inner diameter of .170 the stroke of the bending tool assembly is 2%" and this stroke cannot be reduced materially without losing the free access to the crimping die 17 which is essential for convenient operation of the machine. It would not be practical to use a cylindrical piercing punch .170" in diameter and long enough for a 2%" stroke without sacrificing some of the reliability and high precision of which the illustrated apparatus is capable because of the lost-motion connection between the slides 32, 31 by the boss 36 and the slot 35-. The length of the slot is such as to reduce the stroke of the slide 31 to A.

If very small terminals are to be made, the individual feeding steps can only be set relatively inaccurately by means of the earns 12 and cannot adequately be controlled by a stop at the front edge of the last blank. It is preferred in this case to pierce the openings 53 in the strip 10in a separate operation, and to coil the perforated strip on the reel 9. The relatively small round holes 53 do not significantly weaken the strip, and distortion of the still fiat strip due to coiling and other handling has not been encountered. Obviously, the punch 19a is not needed and may be omitted when pre-punched strip is fed to the aperture forming station.

As is not explicitly shown in the drawing, the several punches 19a, 19b, 19c, 19d are releasably mounted on the tool carrier 16, and releasable die inserts define the openings in the stripper plate 15 and the die plate 14 engaged by the punches, the registration pin 26, and the bending tool assembly 21. The latter is releasably attached on the slide 32, and the ram 43 may be released from the slide 33, and the die 17 from the machine frame 1. The machine may thus be modified quickly for making eyelet terminals of different sizes and terminals having a shapeother than that of an eyelet. Piercing tools other than those illustrated have been used in an obvious manner in making and attaching spade lugs, pin terminals, quickconnect terminals, and others after merely replacing the tools and dies of the illustrated machine.

The bending tool assembly 21 has been shown and described as a unitary tubular member, but it is actually preferred to rnake the assembly of several parts normally fastened to each other in fixed spatial relationship.

While reference has been had above to the strip 10 as being fiat, knurled and serrated strips may be processed on the illustrated apparatus as long as the knurls or serrations do not significantly affect the basic flatness of the strip, and the term fiat as used herein does not exclude such surface irregularities as knurls and serrations.

It should be understood, therefore, that the foregoing disclosure relates only to a preferred embodiment of the invention, and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purpose of the disclosure which do not constitute departures from the spirit and scope of the invention as set forth in the appended claims.

We claim:

1. A method of making terminals and of attaching the terminals to respective conductors which comprises:

(a) intermittently feeding a continuous elongated strip through an aperture forming station to an attaching station in successive steps, whereby respective first and second longitudinal portions of said strip are stationary at said stations between said steps;

(b) forming an aperture in each of said first portions at said aperture forming station;

(0) severing each second portion from the remainder of said strip at said attaching station, each severed second portion constituting a blank;

(d) moving said blank in a direction transverse to the direction of elongation of said strip and thereby draping a part of said blank over an anvil at said attaching station and bending said part into an approximate U-shape;

(e) introducing a conductor into a die; and

(f) clamping said approximately U-shaped part of the bent blank on the conductor in said die,

(1) said transverse moving, draping and clamping of said blank being performed between two successive steps of said feeding.

2. A method as set forth in claim '1, wherein said die has a cavity open in said transverse direction to receive said bent part of said blank, and tapering inwardly, said bent part being clamped on said conductor by inward movement thereof into said cavity.

3. A method as set forth in claim- 1, wherein said steps are of equal length.

4. A method as set forth in claim 1, wherein prior to said forming of each aperture, a locating member is conformingly inserted into a previously formed aperture of said strip to precisely locate said first portion relative to said aperture forming station.

5. A method as set forth in claim 1, wherein said feeding of said strip is interrupted for a predetermined period between each pair of successive steps, and during each of said periods, an aperture is formed in. a respective first portion of said strip.

6. An apparatus for making a terminal and for attaching said terminal to a conductor comprising, in combination:

(a) feeding means for intermittently moving an elongated strip in a longitudinal path;

(b) an aperture forming station at said path including tool means and guide means for guiding said tool means transversely of said path for piercing engagement with a strip moved in said path by said feeding means;

(c) an attaching station at said path and offset from said aperture forming station in the direction of strip movement, said attaching station including (1) cutting means for transversely cutting a blank from the pierced strip,

(2) bending means for bending a part of the blank into an approximate U-shape,

(3) a die having a cavity open toward said bending means for receiving the bent part of said blank,

(4) clamping means in said die for clamping the bent blank part about a conductor introduced into said cavity when the bent blank part enters said cavity,

(5) ram means for forcing the bent blank into said cavity; and

(d) drive means for operating said feeding means, said tool means, said cutting means, said bending means, and said ram means in timed sequence.

7. An apparatus as set forth in claim 6, wherein said drive means include first operating means for operating said feeding means in successive steps separated by intervals, and second operating means for operating said tool means, said cutting means, said bending means and said ram means during said intervals.

8. An apparatus as set forth in claim 7, wherein said second operating means include a lost-motion coupling connecting said tool means to said bending means for delaying operation of said tool means relative to operation of said bending means.

9. An apparatus as set forth in claim 7, wherein said bending means include a bending member, and said tool means include a tool carrier, and said second operating means include means for reciprocating said bending memher and said tool carrier in respective paths extending in a common direction transverse of said path, and lost motion means interposed between said second operating means and said tool carrier for shortening the stroke of reciprocating movement of said tool carrier relative to the stroke of reciprocating movement of said bending member.

10. An apparatus as set forth in claim 9, wherein said second operating means are operatively connected to said bending member, and said lost motion means are interposed between said bending member and said tool carrier.

11. An apparatus as set forth in claim 6, wherein said feeding means move said strip in uniform steps, and said tool means include a carrier member and a plurality of piercing tools mounted on said carrier and offset in the direction of strip movement for simultaneous piercing engagement With respective portions of said strip spaced from each other in said direction by the length of one of said steps.

12. An apparatus as set forth in claim 6, further comprising a registration member, and means securing said registration member against movement in the direction of said path, said drive means including means for moving said registration member transversely of said path into and out of engagement with an aperture formed in said strip by said tool means.

References Cited UNITED STATES PATENTS THOMAS H. EAGER, Primary Examiner US. Cl. X.R. 29-203D 

